Dust and dirt collecting unit for vacuum cleaner

ABSTRACT

The present invention relates to a dust and dirt collecting unit for a vacuum cleaner capable of simultaneously performing a primary cyclonic dust collection and a secondary filter dust collection. The dust and dirt collecting unit of the present invention is arranged on one side of the vacuum cleaner for filtering air containing foreign materials. The dust and dirt collecting unit includes a dust casing which has an inlet formed tangentially on the dust casing with an open top portion. A cover may be arranged for opening and closing the top portion of the dust casing. An outlet is provided at the center of the cover for discharging air from which the foreign materials have been filtered out. A filter assembly installed at a bottom surface of the cover corresponding to the outlet and including a cylindrical filter of which the interior communicates with the outlet, and a separating plate which is coupled with a bottom portion of the filter assembly and extends radially to be spaced apart from an inner circumferential surface of the dust casing by a predetermined gap.

[0001] This application claims the benefit of Korean Patent Application No. 2002-61323 filed on Oct. 8, 2002, which is hereby incorporated by reference for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates generally to vacuum cleaners and, more particularly, to bagless vacuum cleaners. The vacuum cleaner is constructed in such a way that by simply manufacturing a dust and dirt collecting portion within a dust and dirt collecting unit foreign materials can be conveniently discharged.

[0004] 2. Discussion of the Related Art

[0005] A vacuum cleaner is an apparatus for suctioning foreign materials by means of suction force. Typically, a motor installed within a main body of the vacuum cleaner generates a suction force to take in air. Foreign materials may be filtered from the air taken in the main body. Further, the foreign materials are generally filtered out using an envelope shaped paper filter, which blocks foreign materials while allowing air to travel through the filter.

[0006] The use of the filter has disadvantages for the following reasons. Foreign materials accumulate within the paper filter, thereby increasing air flow resistance, and reducing the suction force of the vacuum cleaner. Accordingly, the paper filter must be periodically replaced.

[0007] A proposed method to solve these aforementioned problems is to perform the filtering in a cyclonic fashion. FIG. 1 illustrates a conventional cyclonic vacuum cleaner.

[0008] Referring to FIG. 1, the vacuum cleaner comprises a main body 20 in which a suction means for suctioning air is installed, a connection hose 34 made of a flexible material and connected to communicate with the interior of the main body 20, a variable length extension tube 32 installed to communicate with an end of the connection tube 34, and a suction nozzle 31 for suctioning foreign materials by a suction force generated in the main body 20.

[0009] A detachable dust and dirt collecting unit 21 is mounted in the rear of the main body 20. A collecting unit 21 separates suctioned foreign materials by performing the dust and dirt collection in a cyclonic fashion. A discharge portion 29 is formed at the] side of the main body 20. Air is then filtered and discharged to the atmosphere through the discharge portion 29.

[0010] A pair of wheels 28 is arranged on the main body 20. A power cord 26 for supplying the vacuum cleaner with electric power is installed at a side of the main body 20. The power cord 26 is installed such that it can be wound around a cord reel (not shown) in the main body and may be received into the main body when not in use.

[0011] The dust and dirt collecting unit 21 has a handle 21 a for allowing a user to grasp the unit when mounting or detaching the collecting unit to and from the main body 20. Additionally, a handle 24 is pivotally attached to a top surface of the main body 20, thereby allowing the user to move the apparatus.

[0012] When the user operates the aforementioned vacuum cleaner, a suction force generated in the main body is transmitted to the suction nozzle 31 through the connection hose 34 and the extension tube 32. The degree of suction can be adjusted by a switch 33 a installed on a grip portion 33 coupled to the upper portion of the extension tube 32.

[0013] The suction force allows foreign materials on the floor to enter the main body 20 through the suction nozzle 31, the extension tube 32 and the connection hose 34, and the air with entrained foreign materials is introduced into the dust and dirt collecting unit 21. FIG. 2 illustrates a conventional dust and dirt collecting unit 21

[0014] Referring to FIG. 2, the conventional dust and dirt collecting unit 21 includes a dust casing 23. The dust casing 23 has a container shape with an open top portion. A removable cover 22 may cover the open top portion. The dust casing 23 is provided with an inlet 23 a through which the air containing the foreign materials enters from the suction nozzle 31. The inlet 23 a is arranged tangentially on the surface of the dirt collecting unit 21, so that the air introduced into the collecting unit can flow in a spiral or cyclonic airflow pattern.

[0015] A pair of semicircular separating plates 23 b and 23 c are installed at a lower portion of the interior of the dust casing 23. The separating plates are supported within the dust casing 23. The plates are attached to central shafts 23 d and 23 e and are pivotally mounted onto an inner surface of the dust casing 23. Further, the separating plates 23 b and 23 c are arranged in a horizontal position and may only vertically pivot on the central shafts 23 d and 23 e. The separating plates 23 b and 23 c may be supported in the horizontal position with supporting projections (not shown) formed on the inner surface of the dust casing 23.

[0016] A dust and dirt collection space for collecting the foreign materials is defined at the lower portion under the separating plates 23 b and 23 c. A communicating passage is formed at one side of the separating plate 23 b. Foreign materials can enter the dust and dirt collection space through the communicating passage.

[0017] An outlet 22 a is formed in the center of the cover 22. Filtered air is discharged through the outlet 22 a.

[0018] A cylindrical filter 25 is installed below the outlet 22 a. The filter 25 is detachably mounted to a bottom surface of the cover 22 so that the cylindrical interior of the filter is in communication with the outlet 22 a.

[0019] Next, the operation of the conventional vacuum cleaner and the dust and dirt collecting unit 21 constructed will be discussed. When the motor arranged in the main body 20 of the vacuum cleaner is operated generating a suction force and foreign materials are introduced through the suction nozzle 31. The air is then introduced into the main body 20 via the extension tube 32 and the connection hose 34. Thereafter, the air is introduced into the inlet 23 a of the aforementioned dust casing 23.

[0020] The air stream introduced into the dust casing 23 through the inlet 23 a forms a spiral or cyclonic airflow pattern that flows along the cylindrical inner surface of the dust casing 23. The spiral airflow pattern allows the relatively heavy foreign materials to fall down into the lower portion of the dust casing 23. These foreign materials enter into the bottom of the dust casing 23 through the communicating passage 23 f of the separating plate 23 b.

[0021] The air from which the relatively heavy foreign materials have been removed passes through the filter 25 installed in the center of the dust casing 23 from the outside to the inside of the filter. The finer foreign materials contained in the air are sufficiently filtered out as the air passes through the filter 25.

[0022] Next, the air within the cylindrical filter 25 is discharged through the outlet 22 a formed on a top surface of the cover 22. Additionally, the discharged air from the filter cools the motor in the main body 20 as it passes through the motor. Then, the air is completely discharged from the main body 20 through the discharge portion 29.

[0023] When the vacuum cleaner is operated, foreign materials are accumulated in the dust casing 23. That is, the foreign materials separated out in the cyclonic stream are accumulated below the separating plates 23 b and 23 c located in the dust casing 23. When the amount of accumulated foreign materials is greater than a predetermined level, the foreign materials must be emptied from the dust casing 23.

[0024] To empty the dust and dirt collecting unit 21, it must be separated from the main body 20. After separation, the cover 22 is removed from the collecting unit 21. Once the cover 22 is separated, the filter 25 mounted on the bottom surface of the cover may also be separated. If necessary the separated filter 25 may be cleaned, washed and/or replaced.

[0025] The user then can empty the foreign materials from the dust casing 23 by inverting the dust casing 23. In the inverted position, the separating plates 23 b and 23 c pivot downward on the supporting shafts 23 d, 23 e, respectively, so that the foreign materials which have been accumulated below the separating plates to exit the dust casing 23.

[0026] However, the conventional vacuum cleaner and the dust and dirt collecting unit have the following problems.

[0027] The separating plates 23 b and 23 e are additionally and separately installed within the dust casing 23 so as to perform the dust and dirt collection in the cyclonic fashion. That is, the dust and dirt collecting unit is constructed such that the dust collecting space for accumulating the foreign materials is defined at the lower portion of the dust casing 23 by the separating plates 23 b and 23 c. The separating plates 23 b and 23 c are manufactured separately and then mounted in the dust casing 23.

[0028] The number of parts is high and consequently the manufacturing process becomes complicated as the pair of separating plates is installed in the dust casing 23. Problems such as an undesirable increase of production costs and productivity limitations in the manufacturing process occur due to increase of the number of parts.

[0029] Accordingly, there is a need for a vacuum cleaner which avoids these problems with the prior art.

SUMMARY OF THE INVENTION

[0030] The present invention is directed to dust and dirt collecting unit for use in a cyclonic vacuum cleaner that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.

[0031] Another advantage of the present invention is to provide a dust and dirt collecting unit for a vacuum cleaner, which is mounted to one side of a main body of the vacuum cleaner for filtering suctioned air containing foreign materials. The dust and dirt collecting unit comprises a dust casing with a bottom and side surfaces and a open top portion; an inlet formed tangentially on the dust casing for introducing air into the dust casing; a cover for opening and closing the top portion of the dust casing, the cover having an outlet for discharging air from which the foreign materials have been substantially filtered out; a filter assembly attached to a bottom surface of the cover, said filter assembly including substantially a cylindrical filter arranged such that an interior of the filter communicates with the outlet; and a separating plate which is attached to a bottom portion of the filter assembly that extends radially to be spaced apart from an inner surface of the dust casing by a predetermined gap.

[0032] Another aspect of the present invention is directed to the separating plate that extends radially from a bottom surface of the filter assembly and then slopes downwardly.

[0033] Another aspect of the present invention is directed to a filter assembly that includes a ring-shaped upper frame mounted to communicate with the outlet of the cover, a lower frame spaced apart from the upper frame by a predetermined interval, and the substantially cylindrical filter mounted between the upper and lower frames.

[0034] A further aspect of the present invention is directed to a separating plate formed to be concave with a portion formed at the outer edge of the slope at a predetermined angle.

[0035] A further aspect of the present invention is directed to a separating plate that includes a portion fixed to a bottom surface of the lower frame, and a downwardly sloped portion, which extends radially from the fixed portion.

[0036] The separating plate may be detachably mounted to the lower frame. In addition, the separating plate may be integrally formed with the lower frame.

[0037] For example, the separating plate may be fastened to the lower frame with a screw. Alternatively, the separating plate may be coupled to the lower frame by fastening an elastic hook protruding from a bottom surface of the lower frame into a coupling hole formed on a top surface of the separating plate.

[0038] Additionally, a stop plate is formed with the floor surface of the dust casing.

[0039] According to a further aspect of the present invention, there is provided a vacuum cleaner, comprising: a main body of the vacuum cleaner including a suction source; a guide path for guiding air containing foreign materials introduced into the main body by a suction force generated from the suction source; and a dust and dirt collecting unit detachably mounted to the main body for filtering out the foreign materials contained in the air, wherein the dust and dirt collecting unit comprises: a dust and dirt collecting unit for a vacuum cleaner, adapted to be mounted to a main body of the vacuum cleaner, for filtering suctioned air containing foreign materials, comprising: a dust casing with a bottom and side surfaces and an open top portion; an inlet formed tangentially to the side surface of the dust casing for introducing air into the dust casing; a cover for opening and closing the top portion of the dust casing, the cover having an outlet for discharging air from which the foreign materials have been substantially filtered out; a filter assembly attached to a bottom surface of the cover said filter assembly including a substantially cylindrical filter arranged such that an interior of the filter communicates with the outlet; and a separating plate which is attached to a bottom portion of the filter assembly and extends radially to be spaced apart from an inner surface of the dust casing by a predetermined gap.

[0040] According to a still further aspect of the present invention, there is provided a vacuum cleaner, comprising: a main body of the vacuum cleaner including a suction source; a guide path for guiding air containing foreign materials introduced into the main body by a suction force generated from the suction source; and a dust and dirt collecting unit detachably mounted to the main body for filtering out the foreign materials contained in the air, wherein the dust and dirt collecting unit comprises: a dust and dirt collecting unit for a vacuum cleaner adapted to be mounted to a main body of the vacuum cleaner for filtering suctioned air containing foreign materials, comprising: a dust casing with an open top portion; an inlet formed tangentially to the dust casing for introducing air into the dust casing; a cover for opening and closing the top portion of the dust casing, said cover having an outlet for discharging air from which the foreign materials have been substantially filtered out; a filter assembly attached to a bottom surface of the cover corresponding to the outlet, said filter assembly including a substantially cylindrical filter arranged such that an interior of the filter communicates with the outlet; a separating plate which is attached to the bottom portion of the filter assembly and extends radially to come into close contact with an inner surface of the dust casing; and a communicating passage formed on at least a portion of the separating plate to allow the foreign materials to pass therethrough and into a bottom portion of the dust casing.

[0041] Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

[0042] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWING

[0043] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.

[0044] In the drawings:

[0045]FIG. 1 is a perspective view of a conventional vacuum cleaner;

[0046]FIG. 2 is a perspective view of a conventional dust and dirt collecting unit;

[0047]FIG. 3 is a perspective view of a dust and dirt collecting unit according to the present invention;

[0048]FIG. 4 is a sectional front view of the dust and dirt collecting unit according to the present invention;

[0049]FIGS. 5a to 5 c are sectional views of the dust and dirt collecting unit according to the present invention; and

[0050]FIG. 6 is a perspective view of a dust casing of the dust and dirt collecting unit according to the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0051] Reference will now be made in detail to embodiments of the present invention, an example of which is illustrated in the accompanying drawings.

[0052]FIG. 3 is a perspective view of a dust and dirt collecting unit according to the present invention and FIG. 4 is a sectional front view of the dust and dirt collecting unit according to the present invention. Referring to FIGS. 3 and 4, the dust and dirt collecting unit of the present invention comprises a dust casing 100 having an open top portion and a removable cover 200 which may be arranged on the top portion of the dust casing 100.

[0053] The dust casing 100 may have a substantially cylindrical shape with an open end at the top. A handle 112 is formed at a rear portion of the dust casing 100. The handle 112 allows a user to insert the dust casing 100 into or remove from the main body of the vacuum cleaner.

[0054] The dust casing 100 includes an inlet 110 through which air containing foreign materials is introduced. The inlet 110 is positioned at an upper portion of the dust casing 100 and arranged tangentially on the surface of the dust casing 100. Accordingly, the air introduced into the dust casing can flow in the form of a spiral or cyclonic air flow pattern.

[0055] The cover 200 may be arranged on the dust casing 100 so that the dust casing 100 can be open and closed. An outlet 210 is formed in the center of the cover 200, and the outlet may be substantially circular. The outlet is formed such that the filtered air, that is, air that has been subjected to a primary cyclonic dust and dirt collection process and then secondarily passed through a filter for additional dust and dirt collection, can be discharged to the atmosphere.

[0056] A cylindrical filter assembly F is mounted at a bottom surface of the cover 200. The filter assembly F comprises a ring-shaped upper frame 224, a ring-shaped lower frame 222 spaced apart downwardly from the upper frame 224 by a predetermined interval, and a cylindrical filter 220 mounted between the upper and lower frames 224 and 222, respectively.

[0057] The upper frame 224 and lower frame 222 may be made of a synthetic resin material and connected with the filter 220 in between. The filter 220 is substantially cylindrical and formed between the upper and lower frames. Foreign materials are further filtered out as the air passes through the filter 220.

[0058] The upper frame 224 is aligned with the outlet 210 when the filter 220 is arranged on the cover 200. Accordingly, the inner cylindrical space of the filter 220 is in communication with the outlet 210, and as the air passes through the filter 220 it will be discharged through the outlet 210.

[0059] A separating plate 230 is installed below the ring-shaped lower frame 222. The separating plate 230 extends outwardly in a radial direction and these foreign materials that fall out from the air stream may be collected on the separating plate 230 during the cyclonic operation in the dust casing 100.

[0060] The filter 220 may be made of paper or synthetic resin material. The filtration of the cylindrical filter is improved when the contact area of the filter with the air passing into the filter becomes larger. Accordingly, it is preferable that the filter 220 has circumferential undulation formed on an outer surface. For example, referring to FIGS. 3, 4, 5 a, 5 b, and 5 c, the circumferential undulation is formed on the outer surface of the filter with a plurality of straight pleats formed in a vertical direction, thereby maximizing the contact area with the air passing into the filter from the outside and improving the filtration.

[0061] The separating plate 230 extends radially outward and is spaced apart from an inner sidewall of the dust casing 100 by a predetermined gap. In operation, foreign materials are entrained into the air inlet 110. These materials will fall to the floor surface of the dust casing 100 through the gap defined between the separating plate 230 and the inner sidewall of the dust casing 100.

[0062] A dust and dirt collecting space in which the foreign materials are accumulated is defined below the separating plate 230.

[0063] The separating plate 230 according to the illustrated embodiment of the present invention includes a fixed portion 231 which is tightly fixed to a bottom surface of the substantially horizontal lower frame 222, and a downwardly sloped portion 232 which in an radially outward from the fixed portion.

[0064] This sloped portion 232 allows foreign materials to be smoothly guided along this portion 232 and into the collecting space.

[0065] Referring to FIGS. 4 and 5a-5 c, a portion 234 is formed at the outer edge of the sloped portion 232 and extends at a predetermined angle from the sloped portion 232. Accordingly, the separating plate 234 is concave. Therefore, foreign materials separated during the cyclonic separating process may be substantially prevented from rising above the separating plate 230 after they enter the collecting space.

[0066] A structure for mounting the separating plate 230 to the bottom of the filter assembly F will be hereinafter explained with reference to FIGS. 5a to 5 c.

[0067] Referring to FIG. 5a, the separating plate 230 may be attached to the lower frame 222 of the filter assembly F with a fixing device. The fixing device can be a screw, bolt, clip, and/or other suitable fixing unit S. That is, the separating plate 230 may be removable and may be manufactured separately from the filter assembly.

[0068] Alternatively, referring to FIG. 5b the separating plate 230 may be integrally formed with the lower frame 222. For example, the separating plate 230 may be formed with the lower frame 222 during injection molding of the lower frame 222. Thereby, the process of assembling the separating plate 230 can be eliminated.

[0069] Optionally, referring to FIG. 5c an elastic hook 220 a is formed to protrude downward from the bottom surface of the lower frame 222, and a coupling hole 230 a is formed at the center of the separating plate 230 to be resiliently coupled with the elastic hook 220 a. As the elastic hook 220 a has elasticity in a radial direction, it can be retreated inwardly and then be resiliently expanded outwardly again when it is coupled with the hole 230 a. The elastic hook 220 a allows the plate 230 to be attached to the bottom surface of the lower frame 222.

[0070] Additionally, it is apparent that the other structures and methods for attaching the separating plate 230 to the bottom surface of the lower frame 222 may be utilized, in addition to those shown in FIGS. 5a-5 c.

[0071] Referring to FIG. 6, a stop plate 114 protrudes from the floor surface of the dust casing 100. As described above, foreign materials are separated from the air swirling in the dust casing 100 and heavier materials fall onto the floor surface of the dust casing 100. The stop plate 114 substantially prevents foreign materials from continuously swirling in the dust casing 100. That is, foreign materials are substantially caused to stop swirling in the dust casing and are collected near the stop plate 114 when they collide against the stop plate 114. Moreover, the stop plate 114 substantially prevents the foreign materials from being lifted from the surface of the dust casing 100 by the cyclonic airflow.

[0072] Referring now to FIGS. 3 and 4, the overall operation of the dust and dirt collecting unit according to the present invention will now be explained.

[0073] In operation, the suction force causes air containing the foreign materials to be suctioned through the suction nozzle. The foreign materials entrained in the air is introduced into the dust casing 100 through the inlet 110 of the dust casing 100 and the top portion is closed by the cover 200.

[0074] The air stream introduced through the inlet 110 follows spiral airflow pattern since the inlet 110 is arranged tangentially on the dust casing 100.

[0075] The relatively heavier foreign materials entrained in the spiral airflow fall out due to gravity. These heavier foreign materials fall onto the floor surface of the dust casing 100 through the gap defined between the separating plate 230 and the inner sidewall of the dust casing 100. A portion of the foreign materials fall directly through the gap and another portion is guided through the gap after falling onto the sloped portion 232 of the separating plate 230.

[0076] The foreign materials, which have fallen onto the floor surface of the dust casing 100 during the cyclonic dust-collecting process are substantially prevented from further movement by the stop plate 114 and are collected near the stop plate.

[0077] As explained in detail above, cyclonic dust and dirt collection is primarily performed in the dust casing 100. This is done such that the heavy foreign materials contained in the air are accumulated onto the floor surface of the dust casing 100, while there is a continuous air stream swirling in the dust casing.

[0078] After the primary dust and dirt collection has been completed, a secondary dust and dirt collection is performed. The secondary dust and dirt collection removes fine dust and dirt by filtration through a filter 220.

[0079] That is, the finer foreign materials are filtered out while the air within the dust casing 100 passes through the cylindrical filter 220. Therefore, the air filtered with filter 220 is substantially clean air. After passing through the filter 220, the air is then discharged through the outlet 210 formed in the cover 200. Additionally, the discharged air from the outlet 210 cools the motor in the main body. Subsequently, this air is completely discharged to the outside of the vacuum cleaner.

[0080] As described above, an aspect of the present invention is that the separating plate 230 is installed directly to the filter assembly F, for example, which is mounted to the bottom surface of the cover 200 used to open and close the open top portion of the dust casing 100.

[0081] Another embodiment of the separating plate 230 according to the present invention will now be explained.

[0082] In the previous embodiment, a predetermined gap or space is defined between the outer peripheral surface of the separating plate 230 and the inner circumferential surface of the dust casing 100. That is, the size of separating plate 230 is selected to have a predetermined gap between the outer peripheral surface and the inner circumferential surface of the dust casing 100.

[0083] The separating plate 230 of the present invention defines a dust and dirt collecting space so that the foreign materials that fall down onto the floor surface of the dust casing 100 during the cyclonic dust collecting process can be collected in the dust casing. The separating plate can be modified in various manners.

[0084] For example, the separating plate 230 may be constructed such that at least a portion of the outer surface contacts the inner surface of the dust casing 100. A cut out portion 300 may be formed adjacent to an outer periphery of the separating plate 230 and a passage guides foreign materials into the dust collecting space defined below the separating plate 230, a communicating passage through which the foreign materials can fall down into the space should be formed by cutting out at least a portion of an outer periphery of. The foreign materials may be guided below the separating plate 230 through the cut out portion 300 in the separating plate 230.

[0085] The foreign materials can be guided below the separating plate 230 through the communicating passage formed by cutting out at least a portion of the outer periphery of the separating plate 230. In this alternate embodiment, the remainder of the separating plate 230 comes into close contact with the inner circumferential surface of the dust casing 100, thereby creating a passage through the cut out portion 300. Additionally, the cut out portion 300 may be formed in a number of different shapes and arranged in different locations on the separating plate 230.

[0086] The present invention has the following advantages:

[0087] The dust and dirt collecting unit of the present invention performs the primary cyclonic dust and dirt collection and the second filtration for filtering out the finer dust and dirt using the filter.

[0088] Further, the separating plate allows the separated foreign materials to accumulate on the floor surface of the dust casing in a remarkably simpler manner as compared with the conventional one, because the separating plate is installed directly to the bottom of the filter assembly, for example.

[0089] Furthermore, production cost reduction and productivity improvement can be expected as the number of parts is decreased.

[0090] It will be apparent to those skilled in the art that various modifications and variation can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 

What is claimed is:
 1. A dust and dirt collecting unit for a vacuum cleaner, adapted to be mounted to a main body of the vacuum cleaner, for filtering suctioned air containing foreign materials, comprising: a dust casing with a bottom and side surfaces and an open top portion; an inlet formed tangentially to the side surface of the dust casing for introducing air into the dust casing; a cover for opening and closing the top portion of the dust casing, the cover having an outlet for discharging air from which the foreign materials have been substantially filtered out; a filter assembly attached to a bottom surface of the cover, said filter assembly including a substantially cylindrical filter arranged such that an interior of the filter communicates with the outlet; and a separating plate attached to a bottom portion of the filter assembly and extending radially to be spaced apart from an inner surface of the dust casing by a predetermined gap.
 2. A dust and dirt collecting unit for a vacuum cleaner adapted to be mounted to a main body of the vacuum cleaner for filtering suctioned air containing foreign materials, comprising: a dust casing with an open top portion; an inlet formed tangentially to the dust casing for introducing air into the dust casing; a cover for opening and closing the top portion of the dust casing, said cover having an outlet for discharging air from which the foreign materials have been substantially filtered out; a filter assembly attached to a bottom surface of the cover corresponding to the outlet, said filter assembly including a substantially cylindrical filter arranged such that an interior of the filter communicates with the outlet; a separating plate attached to bottom portion of the filter assembly and extending radially to come into close contact with an inner surface of the dust casing; and a communicating passage formed on at least a portion of the separating plate to allow the foreign materials to pass therethrough and into a bottom portion of the dust casing.
 3. The dust and dirt collecting unit of claim 1, wherein the separating plate extends radially from a bottom surface of the filter assembly and then slopes downwardly.
 4. The dust and dirt collecting unit of claim 2, wherein the separating plate extends radially from a bottom surface of the filter assembly and then slopes downwardly.
 5. The dust and dirt collecting unit of claim 1, wherein the filter assembly includes a ring-shaped upper frame mounted to communicate with the outlet of the cover, a lower frame spaced apart from the upper frame by a predetermined interval, and the substantially cylindrical filter mounted between the upper and lower frames.
 6. The dust and dirt collecting unit of claim 3, wherein the separating plate has a portion extending downwardly from an outer edge of the sloped portion.
 7. The dust and dirt collecting unit of claim 5, wherein the separating plate includes a portion fixed to a bottom surface of the lower frame, and a downwardly sloped portion which extends radially from the fixed portion.
 8. The dust and dirt collecting unit of claim 5, wherein the separating plate is detachably connected to the lower frame.
 9. The dust and dirt collecting unit of claim 5, wherein the separating plate is integrally formed with the lower frame.
 10. The dust and dirt collecting unit of claim 8, wherein the separating plate is fastened to the lower frame with a screw.
 11. The dust and dirt collecting unit of claim 8, wherein the separating plate is coupled to the lower frame by fastening an elastic hook protruding from a bottom surface of the lower frame into a coupling hole formed on a top surface of the separating plate.
 12. The dust and dirt collecting unit of claim 1, further comprising a stop plate formed with a floor surface of the dust casing.
 13. The dust and dirt collecting unit of claim 1, wherein the filter is formed with a plurality of vertical pleats creating a circumferential undulation on an outer surface of the filter.
 14. A vacuum cleaner, comprising: a main body of the vacuum cleaner including a suction source; a guide path for guiding air containing foreign materials introduced into the main body by a suction force generated from the suction source; and a dust and dirt collecting unit detachably mounted to the main body for filtering out the foreign materials contained in the air, wherein the dust and dirt collecting unit comprises: a dust and dirt collecting unit for a vacuum cleaner, adapted to be mounted to a main body of the vacuum cleaner, for filtering suctioned air containing foreign materials, comprising: a dust casing with a bottom and side surfaces and an open top portion; an inlet formed tangentially to the side surface of the dust casing for introducing air into the dust casing; a cover for opening and closing the top portion of the dust casing, the cover having an outlet for discharging air from which the foreign materials have been substantially filtered out; a filter assembly attached to a bottom surface of the cover said filter assembly including a substantially cylindrical filter arranged such that an interior of the filter communicates with the outlet; and a separating plate attached to a bottom portion of the filter assembly and extending radially to be spaced apart from an inner surface of the dust casing by a predetermined gap.
 15. A vacuum cleaner, comprising: a main body of the vacuum cleaner including a suction source; a guide path for guiding air containing foreign materials introduced into the main body by a suction force generated from the suction source; and a dust and dirt collecting unit detachably mounted to the main body for filtering out the foreign materials contained in the air, wherein the dust and dirt collecting unit comprises: a dust and dirt collecting unit for a vacuum cleaner adapted to be mounted to a main body of the vacuum cleaner for filtering suctioned air containing foreign materials, comprising: a dust casing with an open top portion; an inlet formed tangentially to the dust casing for introducing air into the dust casing; a cover for opening and closing the top portion of the dust casing, said cover having an outlet for discharging air from which the foreign materials have been substantially filtered out; a filter assembly attached to a bottom surface of the cover corresponding to the outlet, said filter assembly including a substantially cylindrical filter arranged such that an interior of the filter communicates with the outlet; a separating plate attached to bottom portion of the filter assembly and extending radially to come into close contact with an inner surface of the dust casing; and a communicating passage formed on at least a portion of the separating plate to allow the foreign materials to pass therethrough and into a bottom portion of the dust casing.
 16. The vacuum cleaner of claim 14, wherein the separating plate extends radially from a bottom surface of the filter assembly and then slopes downwardly.
 17. The vacuum cleaner of claim 14, wherein the separating plate extends radially from a bottom surface of the filter assembly and then slopes downwardly.
 18. The vacuum cleaner of claim 14, wherein the filter assembly includes a ring-shaped upper frame mounted to communicate with the outlet of the cover, a lower frame spaced apart from the upper frame by a predetermined interval, and the substantially cylindrical filter mounted between the upper and lower frames.
 19. The vacuum cleaner of claim 14, wherein the separating plate has a portion extending downwardly from an outer edge of the sloped portion.
 20. The vacuum cleaner of claim 18, wherein the separating plate includes a portion fixed to a bottom surface of the lower frame, and a downwardly sloped portion, which extends radially from the fixed portion.
 21. The vacuum cleaner of claim 18, wherein the separating plate is detachably connected to the lower frame.
 22. The vacuum cleaner of claim 18, wherein the separating plate is integrally formed with the lower frame.
 23. The vacuum cleaner of claim 21, wherein the separating plate is fastened to the lower frame with a screw.
 24. The vacuum cleaner of claim 21, wherein the separating plate is coupled to the lower frame by fastening an elastic hook protruding from a bottom surface of the lower frame and into a coupling hole formed on a top surface of the separating plate.
 25. The vacuum cleaner of claim 14, further comprising a stop plate formed with a floor surface of the dust casing.
 26. The vacuum cleaner of claim 15, further comprising a stop plate formed with a floor surface of the dust casing.
 27. A dust and dirt collecting unit for a vacuum cleaner comprising: a dust casing with a bottom and side and a top portion; an inlet in the dust casing for introducing air into the dust casing; a cover for the top portion of the dust casing, the cover having an outlet for discharging air; a filter assembly coupled to a bottom surface of the cover, said filter assembly including a filter having an interior communicating with the outlet; and a separating plate attached to the filter assembly and extending toward the inner surface of the dust casing and spaced apart from the inner surface of the dust casing by a predetermined gap.
 28. The dust and dirt collecting unit of claim 27, wherein the predetermined gap is chosen to allow foreign materials entering the dust casing through the inlet to optimally pass the gap.
 29. The dust and dirt collecting unit of claim 27, wherein the separating plate extends radially from a bottom surface of the filter assembly and then slopes downwardly.
 30. The dust and dirt collecting unit of claim 29, wherein the separating plate has a portion extending downwardly from an outer edge of the sloped portion.
 31. The dust and dirt collecting unit of claim 27, wherein the filter assembly includes a ring-shaped upper frame mounted to communicate with the outlet of the cover, a lower frame spaced apart from the upper frame by a predetermined interval, and a substantially cylindrical filter mounted between the upper and lower frames.
 32. The dust and dirt collecting unit of claim 31, wherein the separating plate includes a portion fixed to a bottom surface of the lower frame, and a downwardly sloped portion extending radially from the fixed portion.
 33. The dust and dirt collecting unit of claim 31, wherein the separating plate is detachably connected to the lower frame.
 34. The dust and dirt collecting unit of claim 33, wherein the separating plate is fastened to the lower frame with a screw.
 35. The dust and dirt collecting unit of claim 33, wherein the separating plate is coupled to the lower frame by fastening an elastic hook protruding from a bottom surface of the lower frame into a coupling hole formed on a top surface of the separating plate.
 36. The dust and dirt collecting unit of claim 31, wherein the separating plate is integrally formed with the lower frame.
 37. The dust and dirt collecting unit of claim 27, further comprising a stop plate formed with a floor surface of the dust casing. 